Anisakiasis and gastroallergic reactions associated with Anisakis pegreffii infection, Italy

Abstract

Human cases of gastric anisakiasis caused by the zoonotic parasite Anisakis pegreffii are increasing in Italy. The disease is caused by ingestion of larval nematodes in lightly cooked or raw seafood. Because symptoms are vague and serodiagnosis is difficult, the disease is often misdiagnosed and cases are understimated.

Keywords: Anisakis pegreffii; allergic reaction; anisakiasis; gastroallergic anisakiasis; helminth antigens; molecular diagnostic techniques; parasite; sequences analysis DNA; zoonoses; zoonosis.

Figure 1

Maximum-parsimony bootstrap consensus tree inferred by PAUP* (12) for specimens of Anisakis pegreffii nematodes from patients with gastric anisakiasis (HuC1–HuC8) in Italy. Phylogenetic tree was obtained by mitochondrial DNA cox2 sequences analysis (629 bp) of 1,000 pseudoreplicates related to A. pegreffii previously sequenced and deposited in GenBank. AEH indicates A. pegreffii associated with a previously reported case of intestinal anisakiasis . Bootstrap values >70 are reported at the nodes. Sequences at the mitochondrial DNA cox2 shown here have been deposited in GenBank under accession nos: JQ900759, JQ900760, JQ900761, and JQ900762.

Figure 2

Western blot reaction of serum samples from patients HuC1 and HuC2 from Italy showing allergic reaction against Anisakis pegreffii antigens and allergens. M indicates molecular marker; arrow indicates the reaction at 24 kDa (Ani s1). IgE determination was performed with alkaline phosphatase conjugates obtained from goat anti-human IgE. Antigen-antibody binding was visualized by the alkaline phosphatase 5-bromo-4-chloro-3-indolyl phosphate p-nitroblue tetrazolium chloride system until bands appeared. Human serum specimens negative for A. pegreffii were used as controls. HC1 and HC2 represent patient identification numbers HuC1 and HuC2.